7.62 nato is NOT basically the same round as .308 I strongly disagree w/ that statement since it can lead to deadly malfunctions. Wall thickness is different. Chamber pressures are different. The neck tapers at a different point on the case. Some 7.62 brass is much beefier for use in full auto guns. I contacted Federal because they had a discrepancy on their box specs for Gold Medal Match .308 and 7.62x51. The boxes showed different specs. But their website showed the rounds being identical. I called, & initially they told me the website was correct. So I lied, & told them I was shooting through an old mauser, so they double checked. They confirmed the FGMM box specs & told me not to shoot the hotter .308 through old bolt guns. My Rem 700ss 5R & my Saiga .308 shoot both fine. But I wouldn't shoot .308 through an antique.